EXPANDABLE METAL AS BACKUP FOR ELASTOMERIC ELEMENTS

Abstract

Provided is a sealing tool, a method for sealing an annulus within a wellbore, and a well system. The sealing tool, in at least one aspect, includes a sealing assembly positioned about a mandrel. In at least one aspect, the sealing assembly includes one or more elastomeric sealing elements having a width (WSE), the one or more elastomeric sealing elements operable to move between a radially relaxed state and a radially expanded state. In at least this aspect, the sealing assembly includes a pair of expandable metal features straddling the one or more elastomeric sealing elements, each of the pair of expandable metal features comprising a metal configured to expand in response to hydrolysis and having a width (WEM), and further wherein the width (WSE) is at least three times the width (WEM).

Description

BACKGROUND

A typical sealing assembly (e.g., packer, bridge plug, etc.) generally has one or more seal elements or “rubbers” that are employed to provide a fluid-tight seal radially between a mandrel of the sealing assembly and casing into which the sealing assembly is disposed. Such a sealing assembly is commonly conveyed into the casing in a subterranean wellbore suspended from tubing extending to the earth's surface.

To prevent damage to the seal elements while the sealing assembly is being conveyed into the wellbore, the seal elements are carried on the mandrel in a relaxed or uncompressed state in which they are radially inwardly spaced apart from the casing. When the sealing assembly is set, the seal elements radially expand (e.g., both radially inward and radially outward), thereby sealing against the mandrel and the casing. In certain embodiments, the seal elements are axially compressed between element retainers straddling the seal elements on the seal assembly, which in turn radially expand the seal elements. In other embodiments, one or more swellable seal elements are axially positioned between the element retainers, the swellable seal elements configured to radially expand when subjected to one or more different activation fluids.

The seal assembly often includes a number of slips which grip the casing and prevent movement of the seal assembly axially within the casing after the seal assembly has been set. Thus, if weight or fluid pressure is applied to the seal assembly, the slips resist the axial forces on the seal assembly produced thereby, and prevent axial displacement of the seal assembly relative to the casing.

If, however, fluid pressure is applied to an annular space radially between the sealing assembly and the casing, and above or below the seal elements, the seal elements may be displaced axially into the annular space between the seal assembly and the casing as a result of the differential pressure across the seal elements. Additionally, the seal elements may be displaced into voids, spaces, gaps, etc. on the packer, such as into a radial gap between the element retainer and the mandrel. Such displacements of the seal elements may be caused by fluid pressure acting on the seal elements, or may be caused by axial compression of the seal elements when the seal assembly is set.

It is generally undesirable for the seal elements to displace into the above-described gaps, voids, etc. for a number of reasons. For example, if the seal elements displace into the radial gap between the seal assembly and the casing, and it is later desired to retrieve the seal assembly from the well, the presence of the seal element material in the radial gap may make it difficult to axially displace the seal assembly in the casing. More importantly, displacement of the seal element after the seal assembly has been set usually compromises the ability of the seal elements to effectively seal between the casing and the mandrel.

BRIEF DESCRIPTION

Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a well system designed, manufactured, and operated according to one or more embodiments of the disclosure, the well system including a sealing tool including a sealing assembly designed, manufactured and operated according to one or more embodiments of the disclosure;

FIGS. 2A through 2C illustrate various different deployment states for a sealing tool designed, manufactured and operated according to one aspect of the disclosure;

FIGS. 3A through 3C illustrate various different deployment states for a sealing tool designed, manufactured and operated according to an alternative embodiment of the disclosure;

FIGS. 4A through 4C illustrate various different deployment states for a sealing tool designed, manufactured and operated according to an alternative embodiment of the disclosure;

FIGS. 5A through 5C illustrate various different deployment states for a sealing tool designed, manufactured and operated according to an alternative embodiment of the disclosure;

FIGS. 6A through 6C illustrate various different deployment states for a sealing tool designed, manufactured and operated according to an alternative embodiment of the disclosure; and

FIGS. 7A through 7C illustrate various different deployment states for a sealing tool designed, manufactured and operated according to an alternative embodiment of the disclosure.

DETAILED DESCRIPTION

In the drawings and descriptions that follow, like parts are typically marked throughout the specification and drawings with the same reference numerals, respectively. The drawn figures are not necessarily to scale. Certain features of the disclosure may be shown exaggerated in scale or in somewhat schematic form and some details of certain elements may not be shown in the interest of clarity and conciseness. The present disclosure may be implemented in embodiments of different forms.

Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed herein may be employed separately or in any suitable combination to produce desired results.

Unless otherwise specified, use of the terms “connect,” “engage,” “couple,” “attach,” or any other like term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described.

Unless otherwise specified, use of the terms “up,” “upper,” “upward,” “uphole,” “upstream,” or other like terms shall be construed as generally toward the surface of the ground; likewise, use of the terms “down,” “lower,” “downward,” “downhole,” or other like terms shall be construed as generally toward the bottom, terminal end of a well, regardless of the wellbore orientation. Use of any one or more of the foregoing terms shall not be construed as denoting positions along a perfectly vertical axis. Unless otherwise specified, use of the term “subterranean formation” shall be construed as encompassing both areas below exposed earth and areas below earth covered by water such as ocean or fresh water.

The present disclosure describes a seal assembly employing expandable/expanded metal as a backup to an elastomer in a compression set packer or in a swell rubber packer. The expandable/expanded metal may embody many different locations, sizes and shapes within the seal assembly while remaining within the scope of the present disclosure. In at least one embodiment, the expandable/expanded metal reacts with fluids within the wellbore to create a non-elastomeric backup that has minimal extrusion gap. Accordingly, the use of the expandable/expanded metal within the seal assembly minimizes the likelihood of extruding a seal.

FIG. 1 illustrates a well system 100 designed, manufactured, and operated according to one or more embodiments of the disclosure, the well system 100 including a sealing tool 150 including a sealing assembly 155 designed, manufactured and operated according to one or more embodiments of the disclosure. The well system 100 includes a wellbore 110 that extends from a terranean surface 120 into one or more subterranean zones 130. When completed, the well system 100 produces reservoir fluids and/or injects fluids into the subterranean zones 130. As those skilled in the art appreciate, the wellbore 120 may be fully cased, partially cased, or an open hole wellbore. In the illustrated embodiment of FIG. 1, the wellbore 110 is at least partially cased, and thus is lined with casing or liner 140. The casing or liner 140, as is depicted, may be held into place by cement 145.

An example well sealing tool 150 is coupled with a tubing string 160 that extends from a wellhead 170 into the wellbore 110. The tubing string 160 can be a coiled tubing and/or a string of joint tubing coupled end to end. For example, the tubing string 160 may be a working string, an injection string, and/or a production string. The sealing tool 150 can include a bridge plug, frac plug, packer and/or other sealing tool, having a seal assembly 155 for sealing against the wellbore 110 wall (e.g., the casing 140, a liner and/or the bare rock in an open hole context). The seal assembly 155 can isolate an interval of the wellbore 110 above the seal assembly 155 from an interval of the wellbore 110 below the seal assembly 155, for example, so that a pressure differential can exist between the intervals.

In accordance with the disclosure, the seal assembly 155 may include expandable and/or expandable metal therein. The term expandable metal, as used herein, refers to the expandable metal in a pre-expansion form. Similarly, the term expanded metal, as used herein, refers to the resulting expanded metal after the expandable metal has been subjected to reactive fluid, as discussed below. The expanded metal, in accordance with one or more aspects of the disclosure, comprises a metal that has expanded in response to hydrolysis. In certain embodiments, the expanded metal includes residual unreacted metal. For example, in certain embodiments the expanded metal is intentionally designed to include the residual unreacted metal. The residual unreacted metal has the benefit of allowing the expanded metal to self-heal if cracks or other anomalies subsequently arise, or for example to accommodate changes in the tubular or mandrel diameter due to variations in temperature and/or pressure. Nevertheless, other embodiments may exist wherein no residual unreacted metal exists in the expanded metal.

The expandable metal, in some embodiments, may be described as expanding to a cement like material. In other words, the expandable metal goes from metal to micron-scale particles and then these particles expand and lock together to, in essence, assist in preventing extrusion within the sealing assembly. The reaction may, in certain embodiments, occur in less than 2 days in a reactive fluid and in downhole temperatures. Nevertheless, the time of reaction may vary depending on the reactive fluid, the expandable metal used, and the downhole temperature.

In some embodiments, the reactive fluid may be a brine solution such as may be produced during well completion activities, and in other embodiments, the reactive fluid may be one of the additional solutions discussed herein. The expandable metal is electrically conductive in certain embodiments. The expandable metal may be machined to any specific size/shape, extruded, formed, cast or other conventional ways to get the desired shape of a metal, as will be discussed in greater detail below. The expandable metal, in certain embodiments has a yield strength greater than about 8,000 psi, e.g., 8,000 psi+/−50%.

The hydrolysis of the expandable metal can create a metal hydroxide. The formative properties of alkaline earth metals (Mg—Magnesium, Ca—Calcium, etc.) and transition metals (Zn—Zinc, Al—Aluminum, etc.) under hydrolysis reactions demonstrate structural characteristics that are favorable for use with the present disclosure. Hydration results in an increase in size from the hydration reaction and results in a metal hydroxide that can precipitate from the fluid.

The hydration reactions for magnesium is:

Mg+2H₂O→Mg(OH)₂+H₂,

where Mg(OH)₂ is also known as brucite. Another hydration reaction uses aluminum hydrolysis. The reaction forms a material known as Gibbsite, bayerite, and norstrandite, depending on form. The hydration reaction for aluminum is:

Al+3H₂O→Al(OH)₃+3/2H₂.

Another hydration reaction uses calcium hydrolysis. The hydration reaction for calcium is:

Ca+2H₂O→Ca(OH)₂+H₂,

Where Ca(OH)₂ is known as portlandite and is a common hydrolysis product of Portland cement. Magnesium hydroxide and calcium hydroxide are considered to be relatively insoluble in water. Aluminum hydroxide can be considered an amphoteric hydroxide, which has solubility in strong acids or in strong bases. Alkaline earth metals (e.g., Mg, CA, etc.) work well for the expandable metal, but transition metals (Al, etc.) also work well for the expandable metal. In one embodiment, the metal hydroxide is dehydrated by the swell pressure to form a metal oxide.

In an embodiment, the expandable metal used can be a metal alloy. The expandable metal alloy can be an alloy of the base expandable metal with other elements in order to either adjust the strength of the expandable metal alloy, to adjust the reaction time of the expandable metal alloy, or to adjust the strength of the resulting metal hydroxide byproduct, among other adjustments. The expandable metal alloy can be alloyed with elements that enhance the strength of the metal such as, but not limited to, Al—Aluminum, Zn—Zinc, Mn—Manganese, Zr—Zirconium, Y—Yttrium, Nd—Neodymium, Gd—Gadolinium, Ag—Silver, Ca—Calcium, Sn—Tin, and Re—Rhenium, Cu—Copper. In some embodiments, the expandable metal alloy can be alloyed with a dopant that promotes corrosion, such as Ni—Nickel, Fe—Iron, Cu—Copper, Co—Cobalt, Ir—Iridium, Au—Gold, C— Carbon, Ga—Gallium, In—Indium, Mg—Mercury, Bi—Bismuth, Sn—Tin, and Pd—Palladium. The expandable metal alloy can be constructed in a solid solution process where the elements are combined with molten metal or metal alloy. Alternatively, the expandable metal alloy could be constructed with a powder metallurgy process. The expandable metal can be cast, forged, extruded, sintered, welded, mill machined, lathe machined, stamped, eroded or a combination thereof.

Optionally, non-expanding components may be added to the starting metallic materials. For example, ceramic, elastomer, plastic, epoxy, glass, or non-reacting metal components can be embedded in the expandable metal or coated on the surface of the expandable metal. Alternatively, the starting expandable metal may be the metal oxide. For example, calcium oxide (CaO) with water will produce calcium hydroxide in an energetic reaction. Due to the higher density of calcium oxide, this can have a 260% volumetric expansion (e.g., converting 1 mole of CaO may cause the volume to increase from 9.5 cc to 34.4 cc). In one variation, the expandable metal is formed in a serpentinite reaction, a hydration and metamorphic reaction. In one variation, the resultant material resembles a mafic material. Additional ions can be added to the reaction, including silicate, sulfate, aluminate, carbonate, and phosphate. The metal can be alloyed to increase the reactivity or to control the formation of oxides.

The expandable metal can be configured in many different fashions, as long as an adequate volume of material is available for fully expanding. For example, the expandable metal may be formed into a single long member, multiple short members, rings, among others. In another embodiment, the expandable metal may be formed into a long wire of expandable metal, that can be in turn be wound around a downhole feature such as a mandrel. In certain other embodiments, the expandable metal is a collection of individual separate chunks of the metal held together with a binding agent. In yet other embodiments, the expandable metal is a collection of individual separate chunks of the metal that are not held together with a binding agent. Additionally, a delay coating may be applied to one or more portions of the expandable metal to delay the expanding reactions.

Turning to FIGS. 2A through 2C, depicted are various different deployment states for a sealing tool 200 designed, manufactured and operated according to one aspect of the disclosure. FIG. 2A illustrates the sealing tool 200 in a run-in-hole state, and thus its elastomeric sealing element is in the radially relaxed state and its expandable metal features pre-expansion. In contrast, FIG. 2B illustrates the sealing tool 200 with its elastomeric element in the radially expanded state, but its expandable metal features remain pre-expansion. In contrast, FIG. 2C illustrates the sealing tool 200 with its elastomeric element in the radially expanded state and including expanded metal features (e.g., the expandable metal features post-expansion). As disclosed above, the expandable metal may be subjected to a suitable reactive fluid within the wellbore, thereby forming the expanded metal features.

The sealing tool 200, in the illustrated embodiment of FIGS. 2A through 2C, includes a mandrel 210. The mandrel 210, in the illustrated embodiment, is centered about a centerline (C_L). The sealing tool 200, in at least the embodiment of FIGS. 2A through 2C, additionally includes a bore 290 positioned around the mandrel 210. The bore 290, in at least one embodiment, is a wellbore. The bore 290, in at least one other embodiment, is a tubular positioned within a wellbore, such as a casing, production tubing, etc. In accordance with one aspect of the disclosure, the mandrel 210 and the bore 290 form an annulus 280.

In accordance with one embodiment of the disclosure, the sealing tool 200 includes one or more elastomeric sealing elements 220 positioned about the mandrel. The one or more elastomeric sealing elements 220 have a pre-expansion width (W_SE), and are operable to move between a radially relaxed state, such as that shown in FIG. 2A, and a radially expanded state, such as that shown in FIGS. 2B and 2C. While three elastomeric sealing elements 220 are illustrated in FIGS. 2A through 2C, other embodiments exist wherein only a single elastomeric sealing element is employed. In the embodiment of FIGS. 2A through 2C, the one or more elastomeric sealing elements 220 comprise a non-swellable elastomer. Nevertheless, other embodiments exist wherein the one or more elastomeric sealing elements 220 comprise a swellable elastomer.

In the illustrated embodiment of FIGS. 2A through 2C, a pair of metal backup shoes 230 straddle the one or more elastomeric sealing elements 220, and a pair of end rings 240 straddle the pair of metal backup shoes 230. Those skilled in the art understand and appreciate the desire and/or need for the pair of metal backup shoes 230, including preventing extrusion of the one or more elastomeric sealing elements 220. Similarly, those skilled in the art appreciate the desire and/or need for the pair of end rings 240. For example, in the illustrated embodiment of FIGS. 2A through 2C, the pair of end rings 240 are configured to axially slide relative to one another to move the one or more elastomeric sealing elements 220 between the radially relaxed state of FIG. 2A and the radially expanded state of FIGS. 2B and 2C.

With reference to FIG. 2A, the pair of metal backup shoes 230 are expandable metal backup shoes. For example, in accordance with the embodiment of FIG. 2A, the pair of expandable metal backup shoes 230 comprise a metal configured to expand in response to hydrolysis. The pair of expandable metal backup shoes 230 may comprise any of the expandable metals discussed above. Each of the pair of expandable metal backup shoes 230 may have a variety of different shapes, sizes, etc. and remain within the scope of the disclosure. In accordance with one embodiment of the disclosure, each of the pair of expandable metal backup shoes 230 has a pre-expansion width (W_EM). Further to one or more embodiments, the pre-expansion width (W_SE) is at least three times the pre-expansion width (W_EM).

With reference to FIG. 2B, illustrated is the sealing tool 200 of FIG. 2A after setting the one or more elastomeric sealing elements 220. In the illustrated embodiment of FIG. 2B, the one or more elastomeric sealing elements 220 are set by axially moving the pair of end rings 240 relative to another, and thereby moving the one or more elastomeric sealing elements 220 from the radially relaxed state of FIG. 2A to the radially expanded state of FIG. 2B. In the illustrated embodiment of FIG. 2B, the one or more elastomeric sealing elements 220 engage with the bore 290, thereby sealing the annulus 280. Further to the embodiment of FIG. 2B, the pair of expandable metal backup shoes 230 have been mechanically and/or plastically deformed, in this instance also engaging the bore 290. In at least one embodiment, the mechanical deformation may be achieved by adjusting the shape of the expandable metal backup shoes 230. For example, the pair of expandable metal backup shoes 230 could have a scarf cut, spiral cut, or another shape, that allows the pair of expandable metal backup shoes 230 to expand radially as they are axially compressed.

With reference to FIG. 2C, illustrated is the sealing tool 200 of FIG. 2B after subjecting the pair of expandable metal backup shoes 230 to reactive fluid to form a pair of expanded metal backup shoes 250. As disclosed above, the expanded metal backup shoes 250 may include residual unreacted metal. The reactive fluid may be any of the reactive fluid discussed above. In the illustrated embodiment of FIG. 2C, the pair of expanded metal backup shoes 250 at least partially fill the annulus 280, and thereby act as anti-extrusion features for the one or more elastomeric sealing elements 220. The expanded metal backup shoes 250 may additionally have a sealing affect, and thus act as a secondary seal.

In certain embodiments, the time period for the hydration of the expandable metal backup shoes 230 is different from the time period for setting the one or more elastomeric sealing elements 220. For example, the setting of the one or more elastomeric sealing elements 220 might create an elastomeric seal in an hour or less, whereas the expandable metal backup shoes 230 could take multiple hours to several days for the hydrolysis process to fully expand and form the expanded metal backup shoes 250.

Turning to FIGS. 3A through 3C, depicted are various different deployment states for a sealing assembly 300 designed, manufactured and operated according to an alternative embodiment of the disclosure. FIG. 3A illustrates the sealing tool 300 in a run-in-hole state, and thus its elastomeric sealing element is in the radially relaxed state and its expandable metal features pre-expansion. In contrast, FIG. 3B illustrates the sealing tool 300 with its elastomeric element in the radially expanded state, but its expandable metal features remain pre-expansion. In contrast, FIG. 3C illustrates the sealing tool 300 with its elastomeric element in the radially expanded state and including expanded metal features (e.g., the expandable metal features post-expansion). As disclosed above, the expandable metal may be subjected to a suitable reactive fluid within the wellbore, thereby forming the expanded metal features.

The sealing assembly 300 of FIGS. 3A through 3C is similar in many respects to the sealing assembly 200 of FIGS. 2A through 2C. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The sealing assembly 300 differs, for the most part, from the sealing assembly 200, in that the sealing assembly 300 does not employ expandable/expanded metal as its metal backup shoes 230, but includes a separate pair of expandable metal features 310 straddling the one or more elastomeric sealing elements 220, as shown in FIGS. 3A and 3B, and a pair of expanded metal features 350 straddling the one or more elastomeric sealing elements, as shown in FIG. 3C. For example, in the embodiments of FIGS. 3A through 3C, the pair of expandable metal features 310 (FIGS. 3A and 3B) and pair of expanded metal features 350 (FIG. 3C) are positioned axially between the pair of metal backup shoes 230 and the one or more elastomeric sealing elements 220. Otherwise, the process for setting the one or more elastomeric sealing elements 220, and subjecting the pair of expandable metal features 310 to reactive fluid to form the pair of expanded metal features 350, may be the same as that discussed above.

Turning to FIGS. 4A through 4C, depicted are various different deployment states for a sealing assembly 400 designed, manufactured and operated according to an alternative embodiment of the disclosure. FIG. 4A illustrates the sealing tool 400 in a run-in-hole state, and thus its elastomeric sealing element is in the radially relaxed state and its expandable metal features pre-expansion. In contrast, FIG. 4B illustrates the sealing tool 400 with its elastomeric element in the radially expanded state, but its expandable metal features remain pre-expansion. In contrast, FIG. 4C illustrates the sealing tool 400 with its elastomeric element in the radially expanded state and including expanded metal features (e.g., the expandable metal features post-expansion). As disclosed above, the expandable metal may be subjected to a suitable reactive fluid within the wellbore, thereby forming the expanded metal features.

The sealing assembly 400 of FIGS. 4A through 4C is similar in many respects to the sealing assembly 300 of FIGS. 3A through 3C. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The sealing assembly 400 differs, for the most part, from the sealing assembly 300, in that the sealing assembly 400 does not employ a separate pair of expandable metal features 310 straddling the one or more elastomeric sealing elements 220, but includes a separate pair of expandable metal features 410 straddling the pair of metal backup shoes 230, as shown in FIGS. 4A and 4B, and a separate pair of expanded metal features 450 straddling the pair of metal backup shoes 230, as shown in FIG. 4C. For example, in the embodiments of FIGS. 4A through 4C, the pair of metal backup shoes 230 are positioned axially between the pair of expandable metal features 410 (FIGS. 4A and 4B), and pair of expanded metal features 450 (FIG. 3C). Otherwise, the process for setting the one or more elastomeric sealing elements 220, and subjecting the pair of expandable metal features 410 to reactive fluid to form the pair of expanded metal features 450, may be the same as that discussed above.

Turning to FIGS. 5A through 5C, depicted are various different deployment states for a sealing assembly 500 designed, manufactured and operated according to an alternative embodiment of the disclosure. FIG. 5A illustrates the sealing tool 500 in a run-in-hole state, and thus its elastomeric sealing element is in the radially relaxed state and its expandable metal features pre-expansion. In contrast, FIG. 5B illustrates the sealing tool 500 with its elastomeric element in the radially expanded state, but its expandable metal features remain pre-expansion. In contrast, FIG. 5C illustrates the sealing tool 500 with its elastomeric element in the radially expanded state and including expanded metal features (e.g., the expandable metal features post-expansion). As disclosed above, the expandable metal may be subjected to a suitable reactive fluid within the wellbore, thereby forming the expanded metal features.

The sealing assembly 500 of FIGS. 5A through 5C is similar in many respects to the sealing assembly 400 of FIGS. 4A through 4C. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The sealing assembly 500 differs, for the most part, from the sealing assembly 400, in that the sealing assembly 500 includes a delay coating 510 enclosing one or more of the pair of expandable metal features 410, as shown in FIG. 5A. Those skilled in the art understand the purpose for the delay coating, including to delay the reaction of the expandable metal features 410 with the reactive fluid for a given period of time.

In certain instances, the delay coating is a porous material that over time allows the reactive fluid to penetrate therethrough and thereby form the expanded metal features 450. In other embodiments, such as that shown in FIG. 5A, the delay coating is a non-porous material, and thus will fully protect the pair of expandable metal features 410 so long as it remains intact. In accordance with the embodiment of FIG. 5B, the delay coating 510 may be broken during the process for setting the one or more elastomeric sealing elements 220. The delay coating 510 can be an epoxy, a polymer, a metal, a ceramic, or a glass, among others. In one embodiment, the pair of expandable metal features 410 are encapsulated in a nickel delay coating. In this embodiment, the process for setting the one or more elastomeric sealing elements 220 stretches the nickel delay coating. The stretching causes tears in the nickel delay coating, which triggers the hydration in the pair of expandable metal features 410, thereby resulting in the expanded metal features 450. Otherwise, the process for setting the one or more elastomeric sealing elements 220, and subjecting the pair of expandable metal features 410 to reactive fluid to form the pair of expanded metal features 450, may be the same as that discussed above.

Turning to FIGS. 6A through 6C, depicted are various different deployment states for a sealing assembly 600 designed, manufactured and operated according to an alternative embodiment of the disclosure. FIG. 6A illustrates the sealing tool 600 in a run-in-hole state, and thus its elastomeric sealing element is in the radially relaxed state and its expandable metal features pre-expansion. In contrast, FIG. 6B illustrates the sealing tool 600 with its elastomeric element in the radially expanded state, but its expandable metal features remain pre-expansion. In contrast, FIG. 6C illustrates the sealing tool 600 with its elastomeric element in the radially expanded state and including expanded metal features (e.g., the expandable metal features post-expansion). As disclosed above, the expandable metal may be subjected to a suitable reactive fluid within the wellbore, thereby forming the expanded metal features.

The sealing assembly 600 of FIGS. 6A through 6C is similar in many respects to the sealing assembly 400 of FIGS. 4A through 4C. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The sealing assembly 600 differs, for the most part, from the sealing assembly 400, in that each of the pair of expandable metal features 610 is a wire of expandable metal wrapped multiple (e.g., ten or more times) around the mandrel 210. The wire of expandable metal, in at least one embodiment, could have a diameter ranging from 2 mm to 6 mm, thereby providing an increased surface area for the hydrolysis reaction. As is illustrated in FIG. 6C, a pair of expanded metal features 650 would result from the hydrolysis reaction. Otherwise, the process for setting the one or more elastomeric sealing elements 220, and subjecting the pair of expandable metal features 610 to reactive fluid to form the pair of expanded metal features 650, may be the same as that discussed above.

Turning to FIGS. 7A through 7C, depicted are various different deployment states for a sealing assembly 700 designed, manufactured and operated according to an alternative embodiment of the disclosure. FIG. 7A illustrates the sealing tool 700 in a run-in-hole state, and thus its elastomeric sealing element is in the radially relaxed state and its expandable metal features pre-expansion. In contrast, FIG. 7B illustrates the sealing tool 700 with its elastomeric element in the radially expanded state, but its expandable metal features remain pre-expansion. In contrast, FIG. 7C illustrates the sealing tool 700 with its elastomeric element in the radially expanded state and including expanded metal features (e.g., the expandable metal features post-expansion). As disclosed above, the expandable metal may be subjected to a suitable reactive fluid within the wellbore, thereby forming the expanded metal features.

The sealing assembly 700 of FIGS. 7A through 7C is similar in certain respects to the sealing assembly 200 of FIGS. 2A through 2C. Accordingly, like reference numbers have been used to illustrate similar, if not identical, features. The sealing assembly 700 differs, for the most part, from the sealing assembly 200, in that the sealing assembly 700 employs one or more swellable elastomeric sealing elements 720. Thus, in the embodiment of FIGS. 7A through 7C, the one or more swellable elastomeric sealing elements 720 are configured to swell to move between the radially relaxed state and the radially expanded state, as opposed to employing the axially sliding end rings to expand the one or more elastomeric sealing elements 220.

Further to the embodiment of FIGS. 7A through 7C, a pair of expandable metal end rings 710 are employed. In at least one embodiment, the pair of expandable metal end rings 710 comprise a metal configured to expand in response to hydrolysis. The pair of expandable metal end rings 710, in the embodiment of FIGS. 7A through 7C, are axially fixed relative to one another. In yet other embodiments, however, the pair of expandable metal end rings 710 are configured to axially slide relative to one another. Otherwise, the process for setting the one or more elastomeric sealing elements 720, and subjecting the pair of expandable metal end rings 710 to reactive fluid to form the pair of expanded metal features 450, may be the same as that discussed above.

Aspects disclosed herein include:

A. A sealing tool, the sealing tool including: 1) a mandrel; and 2) a sealing assembly positioned about the mandrel, the sealing assembly including: a) one or more elastomeric sealing elements having a pre-expansion width (W_SE), the one or more elastomeric sealing elements operable to move between a radially relaxed state and a radially expanded state; and b) a pair of expandable metal features straddling the one or more elastomeric sealing elements, each of the pair of expandable metal features comprising a metal configured to expand in response to hydrolysis and having a pre-expansion width (W_EM), and further wherein the pre-expansion width (W_SE) is at least three times the pre-expansion width (W_EM).

B. A method for sealing an annulus within a wellbore, the method including: 1) providing a sealing tool within a wellbore, the sealing tool including: a) a mandrel; and b) a sealing assembly positioned about the mandrel, the sealing assembly including: i) one or more elastomeric sealing elements having a pre-expansion width (W_SE), the one or more elastomeric sealing elements operable to move between a radially relaxed state and a radially expanded state; and ii) a pair of expandable metal features straddling the one or more elastomeric sealing elements, each of the pair of expandable metal features comprising a metal configured to expand in response to hydrolysis and having a pre-expansion width (W_EM), and further wherein the pre-expansion width (W_SE) is at least three times the pre-expansion width (W_EM); 2) setting the one or more elastomeric sealing elements by moving the one or more elastomeric elements from the radially relaxed state to the radially expanded state; and 3) subjecting the pair of expandable metal features to reactive fluid to form a pair of expanded metal features.

C. A well system, the well system including: 1) a wellbore extending through one or more subterranean formations; and 2) a sealing tool positioned within the wellbore, the sealing tool including: a) a mandrel; and b) a sealing assembly positioned about the mandrel, the sealing assembly including: i) one or more elastomeric sealing elements having a pre-expansion width (W_SE), the one or more elastomeric sealing elements in a radially expanded state; and ii) a pair of expanded metal features straddling the one or more elastomeric sealing elements, each of the pair of expanded metal features comprising a metal that has expanded in response to hydrolysis.

Aspects A, B, and C may have one or more of the following additional elements in combination: Element 1: wherein the pair of expandable metal features are a pair of expandable metal backup shoes. Element 2: further including a pair of metal backup shoes straddling the one or more elastomeric sealing elements. Element 3: wherein the pair of expandable metal features are positioned axially between the pair of metal backup shoes and the one or more elastomeric sealing elements. Element 4: wherein the pair of metal backup shoes are positioned axially between the pair of expandable metal features and the one or more elastomeric sealing elements. Element 5: further including a pair of end rings straddling the pair of expandable metal features, the pair of end rings configured to axially slide relative to one another to move the elastomeric sealing elements between the radially relaxed state and the radially expanded state. Element 6: wherein the pair of expandable metal features are a pair of end rings straddling the one or more elastomeric sealing elements, the pair of end rings axially fixed relative to one another. Element 7: wherein the one or more elastomeric sealing elements are one or more swellable elastomeric sealing elements configured to swell to move between the radially relaxed state and the radially expanded state. Element 8: further including a delay coating enclosing each of the pair of expandable metal features. Element 9: wherein each of the pair of expandable metal features are a wire of expandable metal wrapped multiple times around the mandrel. Element 10: wherein the setting occurs prior to the subjecting. Element 11: wherein the setting includes radially moving the pair of expandable metal features relative to one another, the radially moving mechanically deforming the pair of expandable metal features, and further wherein subjecting the pair of expandable metal features to the reactive fluid includes subjecting the deformed pair of expandable metal features to the reactive fluid to form the pair of expanded metal features. Element 12: further including a pair of end rings straddling the pair of expandable metal features, wherein the pair of expandable metal features are a pair of expandable metal backup shoes, and further wherein setting the one or more elastomeric elements includes axially sliding the pair of end rings relative to each other to move the one or more elastomeric elements from the radially relaxed state to the radially expanded state. Element 13: further including a pair of metal backup shoes straddling the one or more elastomeric elements, the pair of expandable metal features positioned axially between the pair of metal backup shoes and the one or more elastomeric sealing elements, and further including a pair of end rings straddling the pair of metal backup shoes, and wherein setting the one or more elastomeric elements includes axially sliding the pair of end rings relative to each other to move the one or more elastomeric elements from the radially relaxed state to the radially expanded state. Element 14: further including a pair of metal backup shoes straddling the one or more elastomeric elements, the pair of metal backup shoes positioned axially between the pair of expandable metal features and the one or more elastomeric sealing elements, and further including a pair of end rings straddling the pair of expandable metal features, and wherein setting the one or more elastomeric elements includes axially sliding the pair of end rings relative to each other to move the one or more elastomeric elements from the radially relaxed state to the radially expanded state. Element 15: wherein the pair of expandable metal features are a pair of end rings straddling the one or more elastomeric sealing elements, the pair of end rings axially fixed relative to one another, and wherein setting the one or more elastomeric elements includes subjecting the one or more elastomeric elements to an activation fluid causing the one or more elastomeric elements to swell and move between the radially relaxed state and the radially expanded state. Element 16: further including a delay coating enclosing each of the pair of expandable metal features, and further wherein setting the one or more elastomeric elements breaks the delay coating thereby allowing the reactive fluid to form the pair of expanded metal features. Element 17: wherein each of the pair of expandable metal features are a wire of expandable metal wrapped multiple times around the mandrel.

Those skilled in the art to which this application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments.

Claims

1. A sealing tool, comprising:

a mandrel; and

a sealing assembly positioned about the mandrel, the sealing assembly including: one or more elastomeric sealing elements having a pre-expansion width (WSE), the one or more elastomeric sealing elements operable to move between a radially relaxed state and a radially expanded state; and a pair of expandable metal features straddling the one or more elastomeric sealing elements, each of the pair of expandable metal features comprising a metal configured to expand in response to hydrolysis and having a pre-expansion width (WEM), and further wherein the pre-expansion width (WSE) is at least three times the pre-expansion width (WEM).

2. The sealing tool as recited in claim 1, wherein the pair of expandable metal features are a pair of expandable metal backup shoes.

3. The sealing tool as recited in claim 1, further including a pair of metal backup shoes straddling the one or more elastomeric sealing elements.

4. The sealing tool as recited in claim 3, wherein the pair of expandable metal features are positioned axially between the pair of metal backup shoes and the one or more elastomeric sealing elements.

5. The sealing tool as recited in claim 3, wherein the pair of metal backup shoes are positioned axially between the pair of expandable metal features and the one or more elastomeric sealing elements.

6. The sealing tool as recited in claim 1, further including a pair of end rings straddling the pair of expandable metal features, the pair of end rings configured to axially slide relative to one another to move the elastomeric sealing elements between the radially relaxed state and the radially expanded state.

7. The sealing tool as recited in claim 1, wherein the pair of expandable metal features are a pair of end rings straddling the one or more elastomeric sealing elements, the pair of end rings axially fixed relative to one another.

8. The sealing tool as recited in claim 7, wherein the one or more elastomeric sealing elements are one or more swellable elastomeric sealing elements configured to swell to move between the radially relaxed state and the radially expanded state.

9. The sealing tool as recited in claim 1, further including a delay coating enclosing each of the pair of expandable metal features.

10. The sealing tool as recited in claim 1, wherein each of the pair of expandable metal features are a wire of expandable metal wrapped multiple times around the mandrel.

11. A method for sealing an annulus within a wellbore, comprising:

providing a sealing tool within a wellbore, the sealing tool including: a mandrel; and a sealing assembly positioned about the mandrel, the sealing assembly including: one or more elastomeric sealing elements having a pre-expansion width (WSE), the one or more elastomeric sealing elements operable to move between a radially relaxed state and a radially expanded state; and a pair of expandable metal features straddling the one or more elastomeric sealing elements, each of the pair of expandable metal features comprising a metal configured to expand in response to hydrolysis and having a pre-expansion width (WEM), and further wherein the pre-expansion width (WSE) is at least three times the pre-expansion width (WEM);

setting the one or more elastomeric sealing elements by moving the one or more elastomeric elements from the radially relaxed state to the radially expanded state; and

subjecting the pair of expandable metal features to reactive fluid to form a pair of expanded metal features.

12. The method as recited in claim 11, wherein the setting occurs prior to the subjecting.

13. The method as recited in claim 12, wherein the setting includes radially moving the pair of expandable metal features relative to one another, the radially moving mechanically deforming the pair of expandable metal features, and further wherein subjecting the pair of expandable metal features to the reactive fluid includes subjecting the deformed pair of expandable metal features to the reactive fluid to form the pair of expanded metal features.

14. The method as recited in claim 11, further including a pair of end rings straddling the pair of expandable metal features, wherein the pair of expandable metal features are a pair of expandable metal backup shoes, and further wherein setting the one or more elastomeric elements includes axially sliding the pair of end rings relative to each other to move the one or more elastomeric elements from the radially relaxed state to the radially expanded state.

15. The method as recited in claim 11, further including a pair of metal backup shoes straddling the one or more elastomeric elements, the pair of expandable metal features positioned axially between the pair of metal backup shoes and the one or more elastomeric sealing elements, and further including a pair of end rings straddling the pair of metal backup shoes, and wherein setting the one or more elastomeric elements includes axially sliding the pair of end rings relative to each other to move the one or more elastomeric elements from the radially relaxed state to the radially expanded state.

16. The method as recited in claim 11, further including a pair of metal backup shoes straddling the one or more elastomeric elements, the pair of metal backup shoes positioned axially between the pair of expandable metal features and the one or more elastomeric sealing elements, and further including a pair of end rings straddling the pair of expandable metal features, and wherein setting the one or more elastomeric elements includes axially sliding the pair of end rings relative to each other to move the one or more elastomeric elements from the radially relaxed state to the radially expanded state.

17. The method as recited in claim 11, wherein the pair of expandable metal features are a pair of end rings straddling the one or more elastomeric sealing elements, the pair of end rings axially fixed relative to one another, and wherein setting the one or more elastomeric elements includes subjecting the one or more elastomeric elements to an activation fluid causing the one or more elastomeric elements to swell and move between the radially relaxed state and the radially expanded state.

18. The method as recited in claim 11, further including a delay coating enclosing each of the pair of expandable metal features, and further wherein setting the one or more elastomeric elements breaks the delay coating thereby allowing the reactive fluid to form the pair of expanded metal features.

19. The method as recited in claim 11, wherein each of the pair of expandable metal features are a wire of expandable metal wrapped multiple times around the mandrel.

20. A well system, comprising:

a wellbore extending through one or more subterranean formations; and

a sealing tool positioned within the wellbore, the sealing tool including: a mandrel; and a sealing assembly positioned about the mandrel, the sealing assembly including: one or more elastomeric sealing elements having a pre-expansion width (WSE), the one or more elastomeric sealing elements in a radially expanded state; and a pair of expanded metal features straddling the one or more elastomeric sealing elements, each of the pair of expanded metal features comprising a metal that has expanded in response to hydrolysis.